The aim of the invention is to be able to determine the soot quantity in the exhaust gas of a combustion system by using at least two heatable resistance sensor elements (D). Said aim is achieved by a measuring system that determines a test result in a measuring cycle comprising at least two steps in which the temperature is simultaneously measured by means of a ratiometric measuring method. The respective operating conditions of the individual sensor elements (D) are selected differently in the individual measuring steps, at least one of the sensor elements being measured in the sooty state and at least one other sensor element being used as a reference element in a non-sooty state. Sooty and non-sooty sensor elements (D) are preheated to the same temperature and continue to be heated thereafter for measurement purposes by a defined, especially a constant, excitement parameter, the at least one sooty sensor element being measured below the oxidation temperature of soot. The measurement can be repeated in reversed operating conditions of the sooty and non-sooty sensor elements.
|Translated title of the contribution||SOOT SENSOR COMPRISING HEATABLE TEMPERATURE-DEPENDENT RESISTANCE SENSOR ELEMENTS|
|IPC||G01N 27/ 18 A I|
|Publication status||Published - 17 Feb 2005|